Trajectories Nutrient Dataset for Nitrogen (TREND-Nitrogen)
In this dataset, we synthesize crop production, fertilizer use, population, and atmospheric deposition data to provide county-scale nitrogen (N) fluxes for the contiguous U.S. (1930-2017). The following components of the N mass balance are included: crop N uptake, biological N fixation, N fertilizer, manure N, human N waste, and the total N surplus (net N inputs). Multiple sources were used to construct the dataset, including the U.S. Census of Agriculture, the United States Geological Survey, the National Atmospheric Deposition Program, and the U.S. Census Bureau. Annual-scale data is provided based on gap-filling and data-fusion techniques. The dataset is designed to facilitate multi-decadal investigations of anthropogenic N dynamics across the U.S. in the context of long-term changes in agricultural management and land use.